The exemplary embodiments discussed herein use the example of an oxygen regulator as an illustrative embodiment. Oxygen regulators are generally used to regulate the amount of oxygen supplied to patients who depend on an oxygen supply aid, such as an oxygen tank. Current oxygen regulator gauges express the contents of an oxygen cylinder in terms of pressure, generally measured in pound-force per square inch (PSI), and flow rate, generally measured in liters per minute (l/min). While this information is useful, clinicians generally need to know the time remaining in an oxygen tank so that a new tank can be provided with appropriate planning to ensure safe care of a patient. However, many users of the oxygen tanks are not aware of the method or mathematics required to perform the conversion for a given tank volume from pressure (i.e., PSI) and flow (i.e., liters per minute) into time remaining (i.e., minutes) of oxygen.
For example, presently, when clinicians or other personnel transport patients, a desired flow rate is set and the pressure must be checked to verify that enough oxygen is in a tank to reach the transport destination, including any possible delays. The amount of time remaining is not displayed on the tanks, and therefore transport personnel must be able to make a calculation for a given tank volume from PSI to liters remaining and then divide by the flow rate to obtain the minutes of oxygen remaining in the tank at that flow rate, which typically ranges from 0-15 liters/minute. For a standard E-cylinder, the amount of time in minutes at a given gauge pressure and flow rate in l/min may be calculated with a straightforward calculation. This calculation, when performed and performed accurately, can enable the transport personnel to calculate the remaining minutes of oxygen flow in the tank. What is lacking in the prior art, however, is an improved display assembly that also displays the time remaining until the tank is empty, which is suitable for use with flow regulators. If an oxygen tank runs empty, poor patient outcomes may occur, such as hypoxemia, hypercarbia, and the related consequences.